<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .span1 {
            width: 100px;
            background-color: blue;
        }

        .span2 {
            width: 100px;
            background-color: red;
        }
    </style>
</head>

<body>

    <span class="span1">我是span1</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <span class="span2">我是span2</span>
    <hr>
    <h2>
        normal flow
    </h2>
    <p>
        [说明]:行级元素只占自身大小，如果一行不够，会向下一行移动，符合我们的书写习惯，并且行内元素的高度和宽度都是子元素撑开的。
    </p>


</body>

</html>